const fp = require('lodash/fp')

const cars = [
  {
    name: 'Ferrari FF',
    horsepower: 660,
    dollar_value: 700000,
    in_stock: true
  },
  {
    name: 'Spyker C12 Zagato',
    horsepower: 650,
    dollar_value: 648000,
    in_stock: false
  },
  {
    name: 'Jaguar XKR-S',
    horsepower: 550,
    dollar_value: 132000,
    in_stock: false
  },
  {
    name: 'Audi R8',
    horsepower: 525,
    dollar_value: 114200,
    in_stock: false
  },
  {
    name: 'Aston Martion One-77',
    horsepower: 750,
    dollar_value: 1850000,
    in_stock: true
  },
  {
    name: 'Pagani Huayra',
    horsepower: 700,
    dollar_value: 1300000,
    in_stock: false
  }
]

// 1
let inStock = fp.curry(fp.prop('in_stock'));
// let isLastInStock = fp.flowRight(inStock, fp.last);
let isLastInStock = fp.flowRight(fp.prop('in_stock'), fp.last);
console.log(isLastInStock(cars))

// 2
let firstName = fp.flowRight(fp.prop('name'), fp.first);
console.log(firstName(cars))

// 3
let _average = function(xs) {
  return fp.reduce(fp.add, 0, xs) / xs.length
}

let averageDollarValue = fp.flowRight(_average, fp.map(car => car.dollar_value))
console.log(averageDollarValue(cars))

// 4
let _underscore = fp.replace(/\W+/g, '_')
let sanitizeNames = fp.flowRight(fp.map(name => _underscore(name)));
let names = ['Hello World', 'La Gou'];
console.log(sanitizeNames(names));